1. Field of the Invention
The present invention relates to a method for manufacturing a deposition mask by irradiating a resin film with laser light to form an opening pattern, more particularly to a method for manufacturing a deposition mask so as to control the inclination angle of side walls of the opening pattern, and to a deposition mask manufactured by such method.
2. Description of Related Art
Conventional deposition masks include a mask layer having the thickness of 1 μm to 50 μm. The mask layer has at least one opening pattern corresponding to a deposition pattern. On the mask layer, a magnetic member is disposed not to cover the opening pattern of the mask layer (see JP 2009-249706 A, for example). The opening pattern of the mask layer is desirably tapered to open wide toward the surface facing the magnetic member.
In such conventional deposition masks, the opening pattern is formed, for example, by irradiating a film with laser light shaped in cross section substantially in conformity with the opening pattern. Thus, the inclination angle of side walls of the opening pattern cannot be easily controlled.
Especially if an opening pattern has a rectangular shape in a plan view with two pairs of opposing side walls, the inclination angle for one pair must be the same as that for the other. Accordingly, when deposition is carried out with a deposition mask manufactured by the conventional method while scanning a substrate in one direction, the resultant thin layer shows non-uniform distribution of layer thickness in the direction crossing the scanning direction because the edge of the opening pattern in this direction shadows the substrate.